1. Field of the Invention
The present invention relates to antibodies, including specified portions or variants, specific for at least one Interleukin-6 (IL-6 also known as Interferon β2) protein or fragment thereof, as well as nucleic acids encoding such anti-IL-6 antibodies, complementary nucleic acids, vectors, host cells, and methods of making and using thereof, including therapeutic formulations, administration and devices.
2. Related Art
Interleukin-6 (IL-6) is a pro-inflammatory cytokine that is produced by many different cell types. In vivo, stimulated monocytes, fibroblasts, and endothelial cells represent the main sources of IL-6. Other cells such as macrophages, T and B lymphocytes, granulocytes, keratinocytes, mast cells, osteoblasts, chrondrocytes, glial cells, and smooth muscle cells also produce IL-6 after stimulation (Kishimoto, T., Blood 74:1–10 (1989) and Kurihara, N. et al., J. Immunology 144:4226–4230 (1990)). Several tumor cells also produce IL-6 (Smith, P. C. et al. Cytokine and Growth Factor Reviews 12:33–40 (2001)) and recently IL-6 was indicated to be a prognostic factor for prostate cancer progression (Nakashima, J. et al. Clinical Cancer Research 6:2702–2706 (2000)). IL-6 production can be regulated by IL-6 itself and depending upon cell type, IL-6 can stimulate or inhibit its own synthesis.
IL-6 can bind to the IL-6 receptor expressed on mitogen-activated B cells, T cells, peripheral monocytes, and certain tumors (Ishimi, Y. et al., J. Immunology 145:3297–3303 (1990)). The IL-6 receptor has at least two different components and is composed of an alpha chain called gp80 that is responsible for IL-6 binding and a beta chain designated gp130 that is needed for signal transduction (Adebanjo, O. et al., J. Cell Biology 142:1347–1356 (1998) and Poli, V. et al., EMBO 13:1189–1196 (1994)). The cytokine family which includes IL-6, LIF, Oncostatin M, IL-11, CNTF, and CT-1 all signal through gp130 after binding to their cognate receptors. In addition, all members of the IL-6 cytokine family can induce hepatic expression of acute phase proteins (Bellido, T. et al., J. Clin. Investigation 97:431–437 (1996)). 87908790.
There are at least two major biological functions of IL-6: mediation of acute phase proteins and acting as a differentiation and activation factor (Avvisti, G. et al., Baillieres Clinical Hematology 8:815–829 (1995) and Poli, V. et al., EMBO 13:1189–1196 (1994)). Acute phase proteins are known to regulate immune responses, mediate inflammation, and play a role in tissue remodeling. As a differentiation and activation factor, IL-6 induces B cells to differentiate and secrete antibody, it induces T cells to differentiate into cytotoxic T cells, activates cell signaling factors, and promotes hematopoiesis (Ishimi, Y. et al., J. Immunology 145:3297–3303 (1990)). IL-6 is prominently involved in many critical bodily functions and processes. As a result, physiological processes including bone metabolism, neoplastic transformation, and immune and inflammatory responses can be enhanced, suppressed, or prevented by manipulation of the biological activity of IL-6 in vivo by means of an antibody (Adebanjo, O. et al., J. Cell Biology 142:1347–1356 (1998)).
Although IL-6 is involved in many pathways, IL-6 knockout mice have a normal phenotype, they are viable and fertile, and these animals show slightly decreased number of T cells and decreased acute phase protein response to tissue injury (Kopf M et al., Impaired immune and acute-phase responses in interleukin-6-deficient mice, Nature; 368(6469):339–42, 1994). In contrast, transgenic mice that over-express IL-6 develop neurologic disease such as neurodegeneration, astrocytosis, cerebral vasculogenesis, and these mice do not develop a blood brain barrier (Campbell et al., Neurologic Disease Induced in Transgenic Mice by Cerebral Overexpression of Interleukin 6 PNAS 90: 10061–10065. 1993).
Recent studies have indicated that a Mab to IL-6 can inhibit in vivo growth of prostate tumors (Smith, P. C. and Keller, E. T., The Prostate in press and Okamoto, M. et al., Cancer Research 57:141–146 (1997) and renal carcinoma (Weissglas, M. et al., The Journal of Urology 153:554–557 (1995)). In addition to a direct effect on tumor growth, blocking IL-6 production can also chemo-sensitize and enhance cytotoxic efficacy (Smith, P. C. et al. Cytokine and Growth Factor Reviews 12:33–40 (2001)). Collectively, literature teaches us that blocking IL-6 activity can inhibit bone degradation, tumor growth and cancer cachexia.
Passive immunotherapy employing non-human, polyclonal (e.g., anti-sera) or monoclonal antibodies (Mabs) and fragments thereof (e.g., proteolytic digestion products thereof) are potential therapeutic agents that are being developed as treatments for various diseases. However, antibodies composed of non-human portions are known to elicit an immune response when administered to humans. This immune response makes repeated antibody administration often unsuitable for therapy and may result in an immune complex mediated clearance of the antibodies from circulation, thus reducing the therapeutic benefit to the patients. Examples of conditions that may be attributed to repeat administration of antibodies composed of non-human portions are serum sickness and anaphylaxis.
In an attempt to avoid these and other problems, a number of approaches including chimerization and “humanization” have been pursued to reduce the immunogenicity of the antibodies/fragments thereof. These approaches have produced antibodies having reduced immunogenicity. These antibodies are substantially of human origin, with only the complementary determing regions (CDR's) and certain framework residue that influence CDR conformation being of non human original. Novel human or humanized monoclonal antibodies are therefore particularly useful alone or in combination with existing molecules for immunotherapeutic uses.
Accordingly, there is a need to provide a high affinity, neutralizing chimeric or human antibodies to IL-6 or fragments thereof that overcome one more of these problems, as well as improvements over known antibodies or fragments thereof for use in preventing, treating, ameliorating, or diagnosing conditions related to the IL-6.
Murine monocolonal antibodies to IL-6 produced from a hybridoma cell line are known for example in U.S. Pat. No. 5,618,700. U.S. Pat. No. 5,856,135 discloses reshaped human antibodies to human IL-6 drived from a mouse monoclonal antibody SK2 in which the complementary determining regions (CDR's) from the variable region of the mouse antibody SK2 are transplanted into the variable region of a human antibody and joined to the constant region of a human antibody.
Other murine monoclonal antibodies have been described and categorized as neutralizing, that is preventing receptor binding, or non-neutralizing (Brakenhoff et al, J. Immunol. (1990) (145:561). Among this set of antibodies, neutralizing monoclonal antibodies to IL-6 can be divided into two groups; and the putative epitopes on the IL-6 molecule designated Site I and Site II. Site I prevent binding to the gp80 (IL6R) and therefore prevent gp130 activation. The Site I epitope was further characterized as comprising regions of both amino terminal and carboxy terminal portions of the IL-6 molecule. Site II binders prevent gp130 activation and therefore may recognize a conformational epitope involved in signalling.
A murine IL-6 monoclonal antibody referred to as CLB-6/8 or CLB-8, which has high affinity for IL-6, binds to the Site I epitope, is known (Brakenhoff et al supra), but the antigen binding domains (CDR regions) of this antibody are not known. As described above, however, the murine antibody is highly immunogenic in humans and its therapeutic value is therefore limited. There is thus a continuing need for antibodies to IL-6 that exhibit high affinity and a favorable pharmaceutical profile.